Optimization identification

ABSTRACT

A computer readable medium including executable instructions that when executed perform a method for validating an optimization in generated code using an executable constraints document is provided. The medium can include instructions for relating an assumption to the optimization during code generation. The medium can include instructions for generating the executable constraints document during the code generation, the executable constraints document including information about the relating; and the medium can include instructions for executing the constraints document when the validating is performed, the validating including performing an operation based on a validation result produced by the validating, where the operation includes displaying the validation result to a user, storing the validation result, sending the validation result to a destination, or modifying the generated code.

BACKGROUND INFORMATION

Certain applications, such as system design applications, may requirethat code be generated. For example, an engineer may need to generateexecutable code to run on a target system when designing an applicationfor the target system. The engineer may generate a specification thatincludes assertions about how the code will perform. For example, thespecification may include an assertion that an input signal for thegenerated code will not exceed ±1 volt. A code generator used by theengineer may perform an optimization, such as removing input voltagesaturation checking, since the assertion indicates that the inputvoltage will remain within a certain range.

The generated code may operate on the target system as expected sincethe generated code was designed specifically for the target system. Atsome time later, the generated code may be installed on another targetsystem, such as a newer version of the target system previously used torun the generated code. The engineer that designed the code based oncertain assumptions may no longer be involved with the code, andtherefore, assumptions made by the engineer and/or optimizations made bythe code generator may not be available to persons working with the newtarget system and the generated code.

Since assumptions, optimizations and/or other features related to thegenerated code may not be readily known, the generated code run on thenew target system may need to undergo extensive testing in order toverify that the generated code operates properly. In some situations,diagnostic information may be available for the generated code to assistwith code verification. For example, a human-readable document mayinclude information about static validations for a portion of thegenerated code. This static diagnostic information may be inadequate tovalidate the generated code since the diagnostic information may not beuseable for runtime validation of the generated code (e.g., thediagnostic information may only be relevant to static behavior of thegenerated code).

Testing and verification in systems, such as complicated systems, can bevery costly and may take many days or months to perform since operatorbased testing may be time consuming and static diagnostic informationmay be inadequate to perform complete validations of generated code. Asa result, productivity may decrease and costs may increase whengenerated code is used on systems that can differ from a configurationof a system on which the generated code was originally designed tooperate.

SUMMARY

In accordance with an embodiment, a computer readable medium includingexecutable instructions that when executed perform a method forvalidating an optimization in generated code using an executableconstraints document is provided. The medium can include instructionsfor relating an assumption to the optimization during code generation,where the code generation produces generated code. The medium caninclude instructions for generating the executable constraints documentduring the code generation, the executable constraints documentincluding information about the relating; and the medium can includeinstructions for executing the constraints document when the validatingis performed, the validating including performing an operation based ona validation result produced by the validating, where the operationincludes displaying the validation result to a user, storing thevalidation result, sending the validation result to a destination, ormodifying the generated code.

In accordance with another embodiment, a method for validatingfunctional code in generated code using a document that includesexecutable content is provided. The method may include relating anassumption or an assertion to an optimization during code generationthat produces generated code, where the assertion, assumption, oroptimization are included in the functional code. The method may includegenerating the document during the code generation, where the documentincludes information about the relating in the executable content. Themethod may include validating at least a portion of the functional codeusing the information, where the validating is performed dynamically,and wherein the validating further produces validation information. Themethod may include displaying the validation information to a user,storing the validation information in a storage device, sending thevalidation information to a destination that performs an operation basedon the validation information, or modifying the generated code based onthe validation information.

In accordance with yet another embodiment, a device for documentinggenerated code is provided. The device may include first logic togenerate code that includes an assertion, and generate an executabledocument that maps an assumption to the assertion, where the executabledocument validates the generated code with respect to a new targetdevice based on the mapping. The device may include second logic tostore the generated code or the executable document, send the generatedcode or the executable document to the new target device, or display thegenerated code or the executable document to a user.

In accordance with still another embodiment, a computer readable mediumincluding executable instructions for operating a user interface thatinteracts with a user is provided. The medium can include instructionsfor receiving a user input related to generating code for a targetdevice, where the code generating generates functional code and anexecutable constraints document that maps an assumption to an assertion,where the assertion is in the generated code. The medium may includeinstructions for displaying information about the generated code to theuser in response to the user input, the displayed information mappingthe assumption to the assertion in the generated code to validate thegenerated code with respect to the target device or with respect to anew target device.

In accordance with yet another embodiment, a system for validatinggenerated code is provided. The system may include means for generatingcode from a specification to produce generated code and means forgenerating an executable constraints document during the generating. Thesystem can include means for storing the generated code or theexecutable constraints document and means for validating the generatedcode using the executable constraints document. The system can includemeans for displaying, storing, or sending a validation result to a user,a storage medium, or a destination, respectively.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate one or more embodiments of theinvention and, together with the description, explain the invention. Inthe drawings,

FIG. 1A illustrates an exemplary system that can be used to practice anexemplary embodiment;

FIG. 1B illustrates an alternative exemplary system that can be used topractice an exemplary embodiment;

FIG. 2 illustrates an exemplary relationship between assumptions andgenerated code;

FIG. 3A illustrates an exemplary technique for generating code from adiagram;

FIG. 3B illustrates an exemplary technique that can employ actualarguments and/or formal arguments of a function in generated code;

FIG. 4 illustrates an exemplary functional diagram showing logic thatcan be used to document generated code in an exemplary embodiment;

FIG. 5 illustrates an exemplary data structure for storing informationassociated with code generation in an exemplary embodiment;

FIGS. 6A-C illustrate exemplary application program interfaces that canbe used in exemplary embodiments;

FIG. 7A illustrates an exemplary user interface that can be used toconfigure an exemplary embodiment;

FIG. 7B illustrates an exemplary user interface that can be used todisplay information about generated code in an exemplary embodiment;

FIG. 7C illustrates an exemplary user interface that can display areport related to generated code;

FIGS. 8A and 8B illustrate a flow chart showing exemplary processingthat can be used with an exemplary embodiment;

FIG. 9 illustrates an exemplary architecture for implementing anexemplary embodiment; and

FIG. 10 illustrates an exemplary networked embodiment that can be usedto generate code.

FIG. 11 illustrates an exemplary user interface that can be used toconfigure generated code;

FIG. 12 illustrates an exemplary graphical model from which code can begenerated using the user interface of FIG. 11;

FIG. 13 illustrates generated code that can be produced from thegraphical model of FIG. 12;

FIG. 14 illustrates exemplary initialization code that can be generatedfrom the graphical model of FIG. 12;

FIG. 15 illustrates an exemplary user interface that can be used toconfigure generated code for the graphical model of FIG. 12;

FIG. 16 illustrates generated code that can be created using the userinterface of FIG. 15;

FIG. 17 illustrates exemplary diagnostic code that can be generated forthe graphical model of FIG. 12 using the user interface of FIG. 15;

FIG. 18 illustrates an exemplary user interface that can be used toenter parameters for a model; and

FIG. 19 illustrated exemplary executable code that can be called toverify generated code.

DETAILED DESCRIPTION Overview

The following detailed description of implementations consistent withprinciples of the invention refers to the accompanying drawings. Thesame reference numbers in different drawings may identify the same orsimilar elements. Also, the following detailed description does notlimit the invention. Instead, the scope of the invention is defined bythe appended claims and their equivalents.

Conventional code generators may not be capable of documenting generatedcode in a way that allows assumptions, assertions, optimizations, etc.,to be accurately identified and/or validated at, for example, runtime.For example, a database may contain generated code that was created torun on version 1 of a target device (target 1), where version 1 is nolonger in production. An operator, such as an engineer, may need to runthe generated code on another target system that is currently inproduction. For example, version 2 of the target system (target 2) maybe a replacement for target 1. The engineer may need to verify that codegenerated for target 1 operates correctly on target 2 before target 2can be put into production.

The conventional code generator may not provide the engineer withdocumentation that accurately identifies (static or runtime)assumptions, assertions, optimizations, etc., associated with thegenerated code and/or that allows runtime validation of the generatedcode. As a result, the engineer may have to perform exhaustive testingof the generated code on target 2, or the engineer may not be able touse the generated code at all (e.g., if target 2 is a safety criticalapplication that can only be used when stringent safety, testing,reliability, etc., criteria are met).

Exemplary embodiments, disclosed hereinbelow, document generated code ina way that allows assumptions, assertions, optimizations, proofobjectives, etc., to be captured in a way that allows features of thegenerated code to be identified and/or validated statically anddynamically (e.g., allows optimizations to be validated prior to runtimeor at runtime). Referring to the example above, an exemplary embodimentmay produce generated code for target 1 along with a separate document(e.g., an executable file, an object, etc.), where the document containsinformation (e.g., meta data) about assumptions, assertions,optimizations, proof objectives, etc., that are reflected in thegenerated code.

In one embodiment, the executable document may include self-diagnosticcode that is run to validate generated code. The executable document mayinclude information, such as assumptions, assertions, optimizations,etc., in the document may be in a format that supports identificationand/or validation of specific portions of the generated code at runtime.In one embodiment, the executable document may include code that can beexecuted to observe the behavior of generated code when the generatedcode is run. As a result, exemplary embodiments allow runtime validationof generated code. In another embodiment, the executable document caninclude links that can be used to associate content in the document(e.g., assertions) with features in the generated code (e.g.,optimizations) to allow information in the generated code to be mappedback to a source, such as a specification that was used to produce thegenerated code. In still another embodiment, the document may include anexecutable portion that can be run to observe the generated code and asecond portion that may include text that can be used by an operator tounderstand portions of the generated code, the executable portion of thedocument, or portions of a source document/file (e.g., a specificationthat was used to produce the generated code).

Still referring to the example, the engineer can retrieve generated codefrom the database and run the code on target 2 knowing what assumptions,assertions, optimizations, etc., went into the generated code. Theengineer can use information produced by the executable document to mapthe generated code to specifications related to target 2, to operationalrequirements for target 2, etc. Use of the executable document allowsthe engineer to quickly and accurately determine whether the generatedcode will operate in a determined manner on target 2. The engineer maymake the determination without having to perform exhaustive testingand/or without requiring that the engineer regenerate code for target 2as might be required using conventional techniques. For example,executing the document may indicate that an optimization was made thegenerated code based on an expected input signal to target 1. Theexecutable document may further validate that target 2 can handle theexpected input without saturating or overloading input logic (e.g., aninput interface) on target 2.

Exemplary embodiments may generate various types of documents forgenerated code depending on requirements for a particularimplementation. For example, a document may be a text document thatincludes information (e.g., descriptions) that can be used by theengineer for identifying, validating, verifying, etc., portions ofgenerated code and/or assumptions, assertions, etc., related to theportions of generated code. In another embodiment, the document mayinclude executable code that operates as an observer of the generatedcode, where the executable code in the document can be used to identify,validate, verify, etc., portions of the generated code and/orassumptions, assertions, etc., related to the portions of generatedcode.

Exemplary embodiments may generate a document that is executed in whole(e.g., an executable document) or may generate a document that containsinformation, a portion of which is executable (e.g., a partiallyexecutable document). The executable code in the document may furtherinclude, or may be used with, checklists, reports, specifications, etc.,that can be used by the engineer, other persons, devices (e.g., a codeauditing device), etc. The executable code may further indicate that theoptimization in the generated code is, or is not, valid for target 2.Exemplary embodiments may further generate substantially any number ofexecutable documents or partially executable documents without departingfrom the spirit of the invention. For example, a first document maydocument a first portion of generated code (e.g., the first document maybe a partially executable document) and a second document may document asecond portion of the generated code (e.g., the second document may bean executable document).

Exemplary embodiments may validate and/or document generated codewithout requiring that modifications be made to information input to thecode generator. For example, a specification may operate as an input toa code generator. An exemplary embodiment may generate a constraintsdocument that includes executable information that can be used tovalidate the generated code by mapping portions of the generated codeback to portions of the specification without requiring that a userinsert special commands, characters, etc., into the specification priorto code generation. The constraints document may be an executabledocument or may be a document that includes some executable information(e.g., executable code). Exemplary embodiments may validate/documentgenerated code unobtrusively since modifications to specifications arenot required when generating code. Exemplary embodiments may furtherproduce a constraints document that includes constraints and/orassumptions generated by the code generator itself. For example, a codegenerator may generate constraints and/or assumptions that can be usedfor a first scheduler associated with target 1 and a second schedulerthat is associated with target 2.

Exemplary executable documents that self-verify or self-diagnosegenerated code may identify substantially any type of informationcontained in the generated code. For example, in addition to previouslydiscussed optimizations, assumptions, and/or assertions, information,such as, but not limited to, performance characteristics, threadinformation (e.g., information about thread safety), power consumption,platform dependent decisions (e.g., integer widths, global memoryinitialization, etc.) may be verified and/or validated using anexecutable document.

Exemplary embodiments may capture assumptions, assertions, constraints,proof objectives, etc., from graphical and/or text sources. For example,one embodiment may capture information from a graphical diagram and maystore the information in an executable document. In one implementation,the graphical diagram may include graphical representations (e.g.,blocks, icons, images, etc.) that can capture assertions, assumptions,proof objectives, etc. This implementation may capture information fromthese graphical representations and may store the information in anexecutable document and/or a partially executable document that holdsself-diagnostic code for the graphical diagram. A second embodiment maycapture information from a text based model and may store theinformation in an executable document and/or a partially executabledocument.

Exemplary System

FIG. 1A illustrates an exemplary system 100 that can be configured topractice an exemplary embodiment. System 100 may include specification110, code generator 120, generated code 130, constraints 140 and targetenvironment 150 (hereinafter target 150). System 100 is illustrative andother implementations can take other forms. For example, an alternativeimplementation of system 100 may have fewer components, more components,or components in a configuration that differs from the configuration ofFIG. 1A. The components of FIG. 1A and/or other figures describe herein,may be implemented in hardware based logic, software based logic and/orlogic that is a combination of hardware and software based logic (e.g.,hybrid logic); therefore, the components of FIG. 1A and/or other figuresherein are not limited to a specific type of logic.

Specification 110 may include logic that contains information that canbe provided to code generator 120 to produce generated code 130 and/orconstraints 140. For example, specification 110 may include text, adiagram (e.g., a block diagram), etc. In one embodiment, specification110 may include graphical specification 112 and/or text specification114. Graphical specification 112 may include graphical information, suchas a graphical diagram (e.g., a block diagram) and text specification114 may include text information, such as a document, text-based codereceived from a text editor, etc. Specification 110 can includeinformation entered by a user or information generated by a device, suchas a device that automatically generates a block diagram based on inputinstructions and/or input data.

In an embodiment, specification 110 may be created in response to anobjective, such as an objective that identifies one or more desiredoutcomes that should be achieved when specification 110 is used.Specification 110 may further include assumptions that can act asconstraints in specification 110 and/or in downstream code and/ordevices, such as downstream code generated using specification 110and/or in downstream devices like code generator 120, target 150 and/orother types of downstream devices (not shown in FIG. 1A).

Assumptions can take many forms, such as, but not limited to, integerwidths (e.g., 8, 16, 32, etc., bit widths), fixed point computation,floating point computation, variable widths, hardware features and/orcapabilities, memory resetting or initialization, rate information(e.g., sampling rate, clock rate, etc.), etc. Assumptions may further beassociated with data structures in generated code, functions and/orfunction signatures in generated code, sequencing of functions ingenerated code, and/or tasks associated with functions in generatedcode. Assumptions may apply to an entire specification 110 or toportions of specification 110. For example, an assumption may apply toan entire model or to one or more subsystems in the model. Assumptionsmay further be arranged in hierarchies within specification 110 ifdesired. Exemplary embodiments may capture assumptions in a graphicalmodel using blocks, text, etc., depending on a particular configurationof specification 110. For example, mechanisms within the model may beused to capture the assumptions. In an alternative implementation,mechanisms outside the model (i.e., mechanisms that are disassociatedfrom the model) may be used to relate assumptions to the model.

Embodiments of specification 110 may include still other types ofinformation, such as execution semantics and/or scheduling semantics.For example, execution semantics can include code that identifiessequences in which functions or other types of code are called and/orinformation indicating whether portions of specification 110 are singlerate and/or multi-rate, etc. Scheduling semantics may includeinformation that identifies how portions of specification 110 (e.g.,elements within a block diagram) should be scheduled for properoperation (e.g., proper execution of the block diagram). Schedulingsemantics may further specify types of schedules that can be used withspecification 110, code generator 120, target 150, etc. (e.g., arate-monotonic scheduler, an earliest deadline first scheduler, etc.).Other embodiments of specification 110 may include still other types ofinformation, such as executable requirements, proof objectives, etc.,depending on particular configurations of system 100.

Code generator 120 may include logic that converts specification 110into generated code 130. For example, specification 110 may be in afirst format, such as a block diagram format, and code generator 120 maytransform the block diagram format into another format, such as a sourcecode format that can be run in target 150. For example, code generator120 may transform a block diagram into a source code format, such as C,C++, assembly language, hardware description language (HDL), etc.

Code generator 120 may perform a number of operations (e.g.,transformations) when converting specification 110 into generated code130. For example, in one embodiment, code generator 120 may convertspecification 110 into a number of intermediate representations byperforming intermediate transformations on portions of specification110. For example, code generator 120 may perform a first intermediatetransformation to combine certain blocks from a diagram into a singleblock and a second transformation to label connections to/from blockswith data type information. Embodiments of code generator 120 may beself-contained in that code generator 120 does not require informationfrom other devices, objects, applications, etc., while performing codegeneration; or, code generator 120 may not be self-contained and mayaccept information from other devices, objects, applications, etc.,while performing code generation.

Embodiments of code generator 120 may generate code for specificdevices, environments, etc., such as target 150. For example, codegenerator 120 may use information about target 150 (e.g., integerwidths, shift behavior, memory initialization information, etc.) whencreating generated code 130. Code generator 120 may use informationabout target 150 to ensure that generated code 130 operates in adetermined manner when executed on target 150. For example, embodimentsof code generator 120 may generate assumptions, constraints, etc.,internally when generating code to help ensure generated code 130operates on target 150 and/or code generator 130 may receiveassumptions, constraints, etc., from other logic (e.g., code, devices,etc.) or from a user.

Generated code 130 may include machine-executable instructions that aregenerated by code generator 120 and/or another device (not shown in FIG.1A). Generated code 130 may be in a human-readable form (e.g., sourcecode) that can be processed by a device, or generated code may be in aformat that is not easily interpreted by a human (e.g., binary code). Inone embodiment, generated code 130 may include information that can beused to diagnose code that is used to perform operations in target 150,such as compiler directives, assertion statements, etc. In anotherembodiment, generated code 130 may not include information that can beused to diagnose code that performs operations on target 150.Embodiments of generated code 130 may be run on devices, such as target150 and/or other types of devices.

Constraints 140 may include information that is used to verify and/ordiagnose generated code 130. For example, constraints 140 may be anexecutable file that includes information that can be used to makedeterminations with respect to generated code 130 when the constraints140 is executed. In one embodiment, constraints 140 can be a file thatallows diagnosing generated code 130 statically or dynamically (e.g., atruntime). For example, executable code in constraints 140 may includeinformation that allows assumptions in generated code 130 to beidentified, evaluated, etc. Assume, for sake of example, that codegenerator 120 produces generated code 130 using an assumption thatintegers have a width of 16 bits, where the integer width was determinedbased on information about target 150. Constraints 140 may includeinformation that indicates that generated code 130 is configured for anenvironment that uses 16 bit integers.

Constraints 140 can include substantially any type of information thatcan be used to make a determination with respect to generated code 130.For example, constraints 140 can include runtime information that can beused to make determinations with respect to generated code 130 asgenerated code 130 executes; information about assertions that havelinks to features (e.g., optimizations, etc.) in generated code 130;information about constraints imposed by generated code 130; informationabout emulators that allow generated code 130 to be run on environmentshaving characteristics that differ from characteristics of target 150;etc.

Constraints 140 can be in substantially any format, such as hypertextmarkup language (.html), extensible markup language (.xml), executable(.exe), and/or other types of formats (e.g., .c, .Java, .mat, .cxx,.log, .s, etc.). Constraints 140 may further be generated and/or storedin still other forms. For example, constraints 140 may be a softwareobject that can be used in system 100 to document generated code 130. Instill another embodiment, constraints 140 can include a first portionthat is executable and a second portion that is in another formatamenable to interpretation by a user, such as such text (.txt),Microsoft Word (.doc), etc. The first portion and second portion ofconstraints 140 can be in the same file or may be in separate files thatare related to each other (e.g., via a link, pointer, filename, etc.).Constraints 140 may be associated with generated code 130 insubstantially any number of ways, such as appended to generated code130; linked to generated code 130; embedded in generated code 130, etc.

FIG. 1B illustrates an alternative exemplary system 105 that can be usedto practice an exemplary embodiment. System 105 is illustrative andother implementations can take other forms. System 105 can includespecification 110, code generator 120, generated code 130, constraints140, target 150, database 160, configuration 170, constraint checker180, new target environment 190 (hereinafter new target 190), and user195. Specification 110, code generator 120, generated code 130,constraints 140, and target 150 may operate as described in connectionwith FIG. 1A. In system 105, target 150 may be optional as indicated bythe dashed line.

Database 160 may include logic that contains information that can beused by code generator 120 to generate code. For example, database 160may include a computer-readable medium that stores user information(e.g., information identifying authorized users), temporary results(e.g., intermediate representations), information about target devices(e.g., parameter information, address information, etc.), assumptions,assertions, etc.

Configuration 170 may include logic that includes information that canbe used to configure code generator 120. For example, configuration 170may include information about constraints that should be satisfied forgenerated code 130 to operate correctly on target 150 and/or new target190; information about optimizations that should be made with respect togenerated code 130, etc.

Configuration 170 may be manual 172 or automatic 174 in an exemplaryembodiment. For example, a manual configuration 172 may be implementedbased on one or more user inputs (e.g., via keyboard inputs). Incontrast, an automatic configuration 174 may be generated by a device,such as a host device running code generator 120. In one embodiment,configuration 170 may reside in database 160.

Constraint checker 180 may include logic that checks constraints 140with respect to generated code 130. In one embodiment, constraintchecker 180 may include a software application that checks an executableconstraint document (e.g., constraints 140) that was generated when codewas generated for target 150. Constraint checker 180 may be run againstgenerated code 130 to verify that constraints are satisfied (e.g., toverify that assertions are true). Implementations of constraint checker180 may be implemented in a variety of ways, such as via checklists,test scripts, compiler directives, etc.

An embodiment of constraint checker 180 may be run against generatedcode 130 to determine whether code generated for target 150 will operatein a determined manner when run on new target 190. For example, codegenerator 120 may have performed one or more optimizations whenproducing generated code 130, and constraints 140 may identify theoptimizations, may document reasons why optimizations were performed,etc. Constraint checker 180 may be run against generated code 130 usingconstraints 140 (e.g., by executing constraints 140) when generated code130 is going to be ported onto a device, such as new target 190.Constraint checker 180 may determine whether the optimizations are validfor new target 190 (e.g., by determining whether new target 190 willoperate correctly using the optimizations present in generated code130).

Constraint checker 180 may turn on or may turn off logic in generatedcode 130 and/or constraints 140 to facilitate verification of generatedcode 130 on new target 190. For example, constraint checker 180 may turnon debugging logic (code) in generated code 130 to allow input data thatis out of range on target 190 to be flagged (e.g., an optimization mayhave been performed based on input signals compatible with target 150and the optimization may need to be validated with respect to new target190). Constraint checker 180 may further generate outputs that can beused by devices and/or user 195 to facilitate validation of generatedcode 130. For example, constraint checker 180 may produce information ina human-readable format, such as a checklist, that can be used by user195 to validate generated code 130 with respect to new target 190.

New target 190 may include logic that runs generated code 130 to performan operation. For example, new target 190 may represent a newer versionof target 150, user 195 may include an individual that interacts withportions of system 105 and/or 100. For example, user 195 may interactwith an output (e.g., a checklist, report, etc.) produced by constraintchecker 180 to verify that constraints are satisfied when generated code130 is ported to new target 190. User 195 may further input informationinto system 100 or 105, such as by entering information forspecification 110, configuration 170, etc.

Exemplary Constraint Document

FIG. 2 illustrates an exemplary relationship between a constraintdocument (e.g., constraints 140) and generated code 130. FIG. 2 includesgenerated code 130 and constraints 140. Generated code 130 may includeone or more constraints, such as assumptions or assertions. In oneembodiment, these constraints may include constraints 210, 220, and 230.Constraint 210 may identify that an input signal should be within adetermined range, such as between +V and −V, constraint 220 may identifythat a division operation will never be zero, and constraint 230 mayidentify that an input signal will never be less than zero volts (e.g.,an input pulse will always be between zero volts and +V). In oneembodiment, constraints 210, 220, and 230 may represent assumptions thatare satisfied when generated code 130 operates properly on target 150.

Code generator 120 may generate constraints 140 when producing generatedcode 130, where constraints 140 includes information that identifiesconstraints 210, 220, and 230. Exemplary embodiments of constraints 140may allow assumptions to be captured while transformations occur in codegenerator 120. For example, constraints 140 may include information thatidentifies a particular assumption, information that identifies wherethe assumption occurs in generated code 130, information about why theassumption was made, information about optimizations that were made ingenerated code 130 based on an assumption, etc. For example, A mayinclude executable information (e.g., code) about assumption 210, B mayinclude executable information about assumption 220, and C may includeexecutable information about assumption 230. A, B and C may be used bynew target 190 when generated code 130 is ported thereto to validateassumptions 210, 220, and 230.

Exemplary embodiments of constraints 140 may identify substantially anytype of information in generated code 130. For example, constraints 140may include information about an argument of a function that is ingenerated code 130. In one embodiment, constraints 140 may include aformal argument that indicates one or more variables declared in anargument list for the function contained in generated code 130. Inanother embodiment, constraints 140 may indicate actual arguments forvariables that can be declared outside the function while still beingassociated with the function (e.g., actual arguments that operate asinputs and/or outputs for the function).

Exemplary Code Generation Techniques

FIG. 3A illustrates an exemplary technique for generating code from adiagram. A block diagram 310 may include one or more graphicalrepresentations that identify operations performed within the diagram.For example, a source block may generate data and may make the dataavailable to another block, such as a summation block. The summationblock may add inputs to produce an output. A subsystem may include oneor more elements that perform operations based on an input to produce anoutput. A feedback block may feed data from an output portion of a blockor diagram to an input portion of a block or diagram. An output blockmay receive data and may archive the data (e.g., to a storage device) ormay make the data available to another block or device (e.g., a scopeblock that displays information associated with the output block).

Information in diagram 310 may be represented using a diagram, such as atree diagram 310A. Tree diagram 310A is illustrative of one techniquethat can be used to represent relationships between information indiagram 310 and other embodiments may use other relationships (e.g., anordered list). Tree diagram 310A may represent blocks and/or connectionsassociated with diagram 310. For example, tree diagram 310A mayrepresent blocks as nodes (circles in FIG. 3A) and block diagramconnections as branches of the tree. In one embodiment, tree diagram310A may be processed using logic (e.g., code) to produce a result.

In one embodiment, diagram 310 may be part of specification 110 and maybe operated on by code generator 120. For example, diagram 310 may beprocessed by code generator 120 via a first intermediate transformation320 to produce a first intermediate result. For example, code generator120 may combine certain blocks into a combination block. Code generator120 may send information about first intermediate transformation 320and/or a first intermediate result to constraints 140. For example, codegenerator 120 may send executable information about first intermediatetransformation 320 to constraints 140. Code generator 120 may perform asecond intermediate transformation 330 to produce a second intermediateresult. Information about second intermediate transformation 330 and/ora second intermediate result may further be sent to constraints 140.Code generator 120 may produce generated code 130 based on the first andsecond intermediate transformations 320, 330.

In one embodiment, generated code 130 may be represented via treediagram 130A. For example, tree diagram 130A may represent source code,such as C++ source code, that is generated from diagram 310. Treediagram 130A may be similar to tree diagram 310A in certainimplementations, or tree diagram 130A may differ significantly from treediagram 310A in other implementations. When code generation is complete,constraints 140 may include executable information (e.g., traceabilityinformation 140A) that can be used to map generated code 130 (e.g., tree130A) back to block diagram 310 (e.g., 310A). Alternatively, constraints140 may include non-executable information, alone or in combination withexecutable information.

Information sent from code generator 120 to constraints 140 may be usedby constraints 140 to record information about the operation of codegenerator 120. For example, constraints 140 may include information thatallows a device, such as new target 190, to determine whether generatedcode 130 will operate correctly when installed thereon. In oneembodiment, constraints 140 may include traceability information 140Athat allows identification and validation of operations performed bycode generator 120.

For example, traceability information 140A may include information thatidentifies first intermediate transformation 320, the first intermediateresult, second intermediate transformation 330, the second intermediateresult, and/or generated code 130. Traceability information 140A mayfurther allow first intermediate transformation 320, the firstintermediate result, second intermediate transformation 330, the secondintermediate result, and/or generated code 130 to be validated (e.g., byallowing an optimization associated with second intermediatetransformation 330 to be validated with respect to a device on whichgenerated code 130 will run).

Embodiments that capture relationships using techniques, such as treediagram 310A, may allow characteristics of generated code 130 to becaptured and/or modified abstractly (e.g., without modifying generatedcode 130 itself). Information associated with these techniques may beinserted into generated code 130 to produce instrumented code (e.g.,code that includes diagnostic information) and/or may remain separatefrom generated code 130 (e.g., may be in a document that is distinctwith respect to generated code 130).

FIG. 3B illustrates an exemplary technique that can employ actualarguments and/or formal arguments of a function in generated code 130.For example, the embodiment of FIG. 3B may include code generator 120,generated code 130, constraints 140, block 350, sub-model 355, and model360. Code generator 120, generated code 130, and constraints 140 mayoperate as previously described. Block 350 may include a graphicalrepresentation that can represent one or more execution methods (e.g.,an algorithm, an update method, an input method, an output method,etc.). For example, block 350 may be a graphical icon associated with atime based, state based, event based, etc., block diagram. Block 350 mayinclude an input signal, or value, such as “a” and may include an outputsignal, or value, such as “b.” In one embodiment, input signals andoutput signals may connect block 350 with other blocks.

Sub-model 355 may include a graphical representation that includes block350. For example, block 350 and other blocks may be grouped together asa sub-model, e.g., sub-model 355. Sub-model 355 may provide a techniquefor representing grouped elements (e.g., blocks) within a largerenvironment, such as a graphical model. In one embodiment, sub-model 355may input a signal, or value, such as “a” into block 350 and get anoutput signal, or value, “b” from block 350. Input signals and outputsignals may connect blocks with other blocks, subsystems, sub-models,models, etc.

Model 360 may include a graphical representation that can includesub-models 355 and/or other information, such as subsystems. Embodimentsof model 360 may include instructions that allow systems, such asdynamic systems, to be simulated. In one embodiment, model 360 may serveas a specification to code generator 120. For example, code generator120 may receive specification 110 (e.g., model 360) and may producegenerated code 130 from model 360.

Code generator 120 may produce constraints 140 when generating code,where constraints 140 includes executable information that allowsportions of generated code 130 to be identified and/or validated. Forexample, model 360 may input a signal, or value, such as “A” intosub-model 355 and may get an output signal, or value, “B” from thesub-model 355. In this case, the value “A” which is input to sub-model355 is interpreted by sub-model 355 as value “a” which sub-model 355inputs to block 350. Also, the value “b” output from block 350 tosub-model 355 is interpreted as value “B” in model 360. In the abovecase, the values “a” and “b” are formal arguments (inputs/outputs) ofsub-model 355 and values “A” and “B” are its actual arguments.

Code generator 120 may be configured to capture information about formalarguments of sub-model 355 in constraints 140 so that “a” and “b” can beidentified when they are present in generated code 130. Code generator120 may further identify actual arguments to sub-model 355 (e.g., “A”and “B”). Code generator 120 may include information about actualarguments in constraints 140 when producing generated code 130. Forexample, constraints 140 may be executed to determine whether formalarguments or actual arguments in model 360 behave in a determinedmanner.

For example; as shown in FIG. 3B, generated code 130 may include afunction called “Sub_Model_Fcn” that can include one or more formalarguments (e.g. “a” and “b” in FIG. 3B, or, alternatively, arg 1 or arg2, etc. (not shown in FIG. 3B)). The generated code 130 may also includea function called “Model_Fcn” that can define one or more variables(e.g. “A” and “B”). The function “Model_Fcn‘”’ may include informationassociated with model 360, such as information about sub-model 355and/or block 350. For example, the function “Model_Fcn” may includeanother function “Sub_Model_Fcn” related to sub-model 355. In this acase, the call to the function “Sub_Model_Fcn” may pass the actualarguments, such as “A” and “B.” Arguments (e.g., actual arguments and/orformal arguments) may be used to pass information into or out ofportions of generated code 130 (such as the “Sub_Model_Fcn” function).

Still referring to FIG. 3B, constraints 140 may include information thatallows functions, arguments, variables, etc., in generated code 130 tobe identified and/or related back to model 360, sub-model 355, and/orblock 350. Embodiments of constraints 140 may be used to map one domain(e.g., a generated code domain that includes the “Sub_Model_Fcn”function) to another domain (e.g., a specification domain that includesmodel 360) without requiring that a user insert special instructionsinto either domain.

Constraints 140 may include human-readable and/or machine-readableinstructions that can be operated on by a user and/or a device (e.g., anew target device). Constraints 140 may further include other types ofinformation that may be useful to a user and/or device. For example,constraints 140 may include code that can be used to test generated code130 to determine whether functions in generated code 130 operatecorrectly. Alternatively, constraints 140 may include a checklist thatis used by a user or by a device to, for example, determine that adesired level of code coverage is achieved by generated code 130. Codecoverage, as used herein, may include statement coverage, conditioncoverage, decision/condition coverage, modified condition/decisioncoverage, etc. Embodiments of constraints 140 can further include othertypes of human-readable or machine-readable information.

Embodiments of constraints 140, such as shown in FIG. 3B, can includeinformation that allows relationships among elements (e.g., functions,variables, etc.) in generated code 130 to be identified. For example,generated code 130 may include nested functions, hierarchies offunctions, etc. In an embodiment, constraints 140 may includeinformation that allows the nested functions to be identified and/orthat allows relationships among these functions to be identified. Forexample, generated code 130 may include a reentrant function (e.g., afunction that can be shared by a number of callers without having thecalls interfere with each other) and/or a non-reentrant function.Constraints 140 may be created when code is generated and constraints140 may contain information that allows the reentrant function and/ornon-reentrant function to be identified in generated code 130.Constraints 140 may further include information that allows thefunctions to be related back to a specification from which the reentrantfunction and/or non-reentrant function were generated.

Embodiments of constraints 140 may contain information about processes,objects, other functions, etc., that can call the reentrant functionand/or non-reentrant function and may include information aboutprocesses, objects, other functions, etc., that can receive informationfrom the reentrant function and/or non-reentrant function. In oneembodiment, a user may specify that code generator 120 create thereentrant function and/or non-reentrant function, and in anotherembodiment, code generator 120 may create the reentrant function and/ornon-reentrant function without user intervention. Embodiments ofconstraints 140 may further include code that can be used to test thereentrant function and/or non-reentrant function (e.g., by executingconstraints 140). In an embodiment, constraints 140 can test or validatethe reentrant function or the non-reentrant function at runtime.

Exemplary Functional Diagram

FIG. 4 illustrates an exemplary functional diagram 400 showing logicthat can be used to document generated code in an exemplary embodiment.Components in FIG. 4 can reside on a single device, such as singlecomputing device, or the components of FIG. 4 can be distributed acrossmultiple devices, such as in a networked environment. Moreover, thecomponents of FIG. 4 can be implemented in hardware based logic,software based logic, or a combination of hardware and software basedlogic (e.g., hybrid logic, wetware, etc.). The implementation of FIG. 4is exemplary, and functional diagram 400 may include more components,fewer components, and/or components arranged differently from thearrangement of FIG. 4.

Functional diagram 400 may include evaluation logic 410, specificationlogic 420, configuration logic 430, generation logic 440, constraintlogic 450, optimization logic 460, and validation logic 470. Evaluationlogic 410 may include logic to process instructions or data related touser inputs, code generation, constraints 140, etc. Evaluation logic 410may further process instructions related to other components in diagram400, such as instructions that allow specification logic 420 to interactwith generation logic 440.

Specification logic 420 may include logic to create or readspecification 110. For example, specification logic 420 may generate, ablock diagram in response to user inputs, and/or specification logic 420may maintain information about blocks, connections, input data, outputdata, etc.

Configuration logic 430 may include logic to create or readconfiguration 170 in response to user inputs or instructions related toa device, such as a remote device. Configuration logic 430 may provideinformation to generation logic 440 for use in producing generated code130.

Generation logic 440 may include logic that generates code based oninformation received from specification logic 420 (e.g., specification110) and/or configuration logic 430 (e.g., configuration 170), a user,another device, etc. Generation logic 440 may create generated code 130that can be used with a destination, such as target 150. In oneembodiment, code generator 120 may generate information (e.g.,constraints, assumptions, etc.) that can be used by generation logic 440when code generator 120 generates code.

Constraint logic 450 may include logic that generates or readsconstraints 140 when generation logic 440 is generating code. In oneembodiment, constraints logic 450 may generate constraints 140 withoutrequiring that modifications (e.g., special instructions) be included inspecification 110. Constraint logic 450 may generate a file in whichconstraints 140 are stored, may insert constraints 140 into generatedcode 130 to produce instrumented code, may append constraints 140 togenerated code 130, etc.

Constraint logic 450 may generate constraints 140 in a human-readable ora machine-readable format. For example, constraints logic 450 maygenerate a .txt file for use by an operator of system 100 and/or amachine-readable file (e.g., .exe, .mat, .c, .xml, etc.) for use by amachine. Constraints logic 450 may further generate interfaces toinformation in constraints 140. For example, an embodiment ofconstraints logic 450 may generate an API that allows information to beread from or written to constraints 140. Alternatively, the API may beused to convert information in constraints 140 from a first format to asecond format (e.g., from a human-readable format to a machine-readableformat, from a first machine-readable format to second machine-readableformat, etc.)

Embodiments of constraint logic 450 may further include logic such asreport generation logic, checklist generation logic, etc. For example,constraint logic 450 may generate a report according to a determinedformat (e.g., a reporting format dictated by government regulations),where the report includes information that can be used by a device or aperson to verify the operation of generated code 130 on a device, suchas new target 190.

Optimization logic 460 may include logic that performs optimizationswhen generation logic 440 is generating code. For example, optimizationlogic 460 may determine that an input signal will never approach asaturation threshold associated with target 150. Optimization logic 460may disable or delete saturation detection logic in generated code 130since the saturation detection logic is not needed.

Validation logic 470 may include logic that can be used to validategenerated code 130 and/or other devices, components, objects, etc., insystem 100 or 105. For example, validation logic 470 may operate with areport generated by constraint logic 450 to validate the operation ofgenerated code 130 on new target 190. For example, generated code 130may include an optimization and the report may include information thatidentifies why the optimization was made and where the optimizationresides in the generated code. The report may further include theoriginal code that was replaced by the optimization. Validation logic470 may evaluate generated code 130, the report, and/or informationabout new target 190 (e.g., shift behavior, memory initializationprotocols, data widths, etc.) to determine whether the optimization isvalid for new target 190.

Validation logic 470 may report an error when the validation determinesthat generated code 130 will not operate in a determined manner (e.g.,in a repeatable manner, in a manner that produces a desired result,etc.), may correct the error by removing the optimization and insertingnon-optimized code, may install an emulator on new target 190, where theemulator allows new target 190 to operate like target 150, etc.Validation logic 470 may further generate a checklist that can be usedby an operator or a device to validate generated code 130.

Illustrative Examples

Exemplary embodiments as described in connection with FIGS. 1A, 1B, 2,3A, 3B, and 4 may be used to document and/or validate constraints insubstantially any type of code generation process. For example, agraphical model may be generated using a sample rate of 1 millisecond(ms) and code generated from the model may be designed to run on target150 at a 1 ms sample rate. An operator may retrieve generated code 130from database 160 and may wish to run generated code 130 on new target190. The operator may install generated code 130 on new target 190 andmay try to run generated code 130 at a sample rate of 2 ms, where 2 msis a sample rate that is incompatible with generated code 130.Constraints 140, when executed, may detect the incompatible sample rateand may provide a warning to the operator via a display device. Forexample, constraints 140 may include logic (e.g., code) that evaluatesthe original sample rate in generated code 130 and further evaluates thenew sample rate on new target 190. Constraints 140 may further identifya code portion that specifies the 1 ms sample rate so that the operatorcan study the code portion. Constraints 140 may further identifyoptimizations that were made in the generated code based on the 1 mssample rate.

In a second example, an operator may specify a minimum and maximum rangefor a signal, such as an input signal to a model. Code generator 120 mayperform code generation and may take the specified min/max signal valueinto account during code generation by performing one or moreoptimizations. For example, code generator 120 may determine that target150 can safely handle input signals in excess of the min/max valuesspecified by the operator. Code generator 120 may remove input overloadprotections for input signals in order to optimize generated code 130(e.g., to make generated code 130 run faster than the code would run ifthe overload protections remained in place).

The operator may attempt to run generated code 130 on new target 190.Constraint checker 180 may be used to determine whether generated code130 will safely run on new target 190. Constraint checker 180 maydetermine that new target 190 has a min/max input range that is lessthan the min/max input range for target 150. For example, constraints140 may include logic that checks an input signal and determines whetherthe signal exceeds an allowable range. Constraint checker 180 mayexecute constraints 140 and may run the input signal logic againstgenerated code 130 and/or new target 190 to determine whether generatedcode 130 will work in a determined manner when run on new target 190.Constraint checker 180 may flag a portion of generated code 130 thatoperates on the input signal to indicate that the input signal exceedsthe input range of new target 190. Constraint checker 180 may alsoprovide replacement code that can be used to replace the code portionthat will not operate properly on new target 190.

In a third example, code may be generated for a safety criticalapplication that requires optimizations be mapped to requirements in thecode in order for the code to be valid. An operator may generate codeusing code generator 120. Code generator 120 may produce generated code130 and constraints 140. Generated code 130 may include optimizationsand constraints 140 may include information that validates theoptimizations. For example, constraints 140 may include information thatidentifies optimizations in the generated code, requirements that led tothe optimizations and/or information about a device on which generatedcode 130 will be run. In one embodiment, the information in constraints140 can be annotated to indicate why the optimizations are valid whenrun on new target 190, etc. The operator may execute constraints 140 tovalidate the optimizations.

In a fourth example, code generator 120 may generate code for a discreteintegrator that runs at regular intervals (e.g., once every 1 ms). Sincethe integrator runs at regular intervals, code generator 120 may hardcode the 1 ms timing interval into an equation for the integrator. Codegenerator 120 may produce generated code 130 that contains the hardcoded timing interval. An operator may retrieve generated code 130 andmay try to run generated code 130 on new target 190 using a timing of 2ms. Constraint checker 180 may use constraints 140 to determine that a 2ms interval is incompatible with generated code 130. Constraint checker180 may provide a warning to a user indicating that generated code 130is invalid for an interval of 2 ms. Constraint checker 180 may furtherprovide the operator with information that identifies the hard codedportion of generated code 130 so that the operator can change the timinginterval to an acceptable value. Alternatively, constraint checker 180may automatically change generated code 130 to make generated code validfor a 2 ms interval.

In a fifth example, generated code 130 may include an optimization thatdetermines whether target 150 has a hardware capability or an operatingsystem capability to reset memory (e.g., to zero out a memory beforegenerated code 130 is run on target 150). Generated code 130 may operateproperly on target 150 since target 150 may include a hardware oroperating system memory reset capability. Generated code 130 may beloaded onto new target 190, where new target 190 does not include ahardware or an operating system memory reset capability. Therefore,generated code 130 may not run correctly on new target 190. Constraints140 may include information that detects the incompatibility and furtheridentifies a portion of generated code 130 that will be impacted whenmemory is not reset. Constraints 140 may further include code that canbe inserted into generated code 130 to reset a memory on new target 190so that generated code 130 will operate in a determined manner.Alternatively, constraint checker 180 may operate with constraints 140to detect and/or modify incompatibilities in generated code 130.

In a sixth example, constraints 140 may include code that performsmultiple operations on new target 190, such as code that performsvariable dimensioning, code that performs overflow and/or underflowdetection/protection, code that performs memory initialization, etc.Constraints 140 may perform these operations statically and/ordynamically (e.g., at runtime).

The examples discussed hereinabove and elsewhere are illustrative. Otherembodiments can be implemented in other ways and/or can operate in waysthat differ from implementations and/or operations described hereinwithout departing from the spirit of the invention.

Exemplary Data Structure

FIG. 5 illustrates an exemplary data structure for storing informationassociated with code generation in an exemplary embodiment. Datastructure 500 may be implemented via a computer-readable medium that isused to store information in a machine-readable format. Exemplaryimplementations may use substantially any number of data structures 500to store information associated aspects of generating code (e.g.,storing specification 110, generated code 130, constraints 140,configuration 170, etc.). Implementations of data structure 500 may bepopulated via an operator or a device, such as a computer operated by auser that interacts with specification 110, code generator 120, etc.

In one implementation, data structure 500 may include informationarranged in a row and column format to facilitate interpretation byusers involved in code generation or using generated code on a targetdevice and/or by devices (e.g., code generator 120), logic (e.g.,validation logic 470), etc. Other implementations of data structure 500may be configured in other ways.

Data structure 500 may include file identifier (ID) 510, date 520,objectives 530, assumptions 540, narrative 550, and constraints 560.File ID 510 may include information that identifies a file in whichinformation related to data structure 500 is stored. File ID 510 mayinclude a file name, an address, a link, or other type of informationthat can be used to identify a file or a location (e.g., a memorylocation) in which a file is stored. Date 520 may include informationthat identifies a date and/or time associated with data structure 500.For example, date 520 may include a date on which data structure 500 wascreated, saved, modified, etc.

Objectives 530 may include information that identifies one or moreobjectives associated with data structure 500. For example, objectives530 may identify a file, or may contain information in a field of datastructure 500, that contains a list of objectives for specification 110and/or for generated code 130. The objectives may represent useridentified goals that generated code 130 should achieve when run ontarget 150 and/or new target 190. Generated code 130 may or may not meetobjectives identified in objectives 530.

Assumptions 540 may include information that identifies assumptionsrelated to specification 110, generated code 130, target 150 and/or newtarget 190. For example, specification 110 may be prepared based onassumptions about target 150. Assumptions 540 may include an identifierfor a file that includes the assumptions, or assumptions 540 may includethe assumptions themselves (e.g., a list of assumptions).

Narrative 550 may include information that can be entered by and/orinterpreted by a user or a device. For example, narrative 550 mayinclude information about data structure 500 and/or devices, code, etc.,in system 100 or 105. For example, narrative 550 may include usercomments about observations made while generating specification 110,configuring code generator 120, etc. Assume, for sake of example, that auser observed that code generator 120 had to be initialized using anundocumented sequence of instructions. The user may include notes,diagrams, video clips, etc., about the initialization sequence innarrative 550.

Constraints 560 may include information about constraints that arerelated to generated code 130; specification 110; devices, components,objects, etc., in system 100, 105, etc.; devices, components, objects,etc., in system 100 or 105; etc. In one embodiment, constraints 140 maybe stored in constraints 560. In another embodiment, constraints 560 mayinclude a link, pointer, file name, etc., that identifies a locationwhere constraints 140 can be found.

Exemplary Application Program Interfaces

FIGS. 6A-C illustrate exemplary APIs that can be used in exemplaryembodiments. These APIs may be code-based interfaces that can be used bysystems, devices, objects, etc., to exchange information with anothersystem, device, object, etc. For example, APIs may include datainterfaces, function interfaces, execution interfaces (e.g., callsequence, call graphs, etc.), timing interfaces (e.g., task, sampletime, etc.), etc. to allow information exchanges in systems 100 or 105.APIs may further provide mappings between generated code and higherlevel languages. Embodiments of APIs may be adapted for transmissionfrom one device, component, object, etc., to another, e.g., by appendinga header to an API to allow the API to be sent over a network to adestination.

FIG. 6A illustrates API 600 that can be used to create specification 110in an exemplary embodiment. API 600 may include input portion 603 andoutput portion 604. Input portion 603 may include information and/oridentifiers that can be used to make information available tospecification 110 (e.g., data, instructions, identifiers, etc.). In oneembodiment, input portion 603 may include user commands 605, retrieveddata 610, and miscellaneous 615.

User commands 605 may include information received from a user. Forexample, a user may enter commands via an input device, such as akeyboard, mouse, trackball, microphone, touch sensitive display,biometric input device, etc. User commands may include instructions tocreate code, blocks, links (e.g., signal paths), data, etc. Retrieveddata 610 may include information retrieved from a location, such as astorage location. For example, specification 110 may include acombination of user generated information and machine generatedinformation, where the machine generated information is made availableto specification 110 from a memory location. Miscellaneous 615 mayinclude other types of information, such as parameter settings,comments, etc.

Output portion 604 may include information and/or identifiers thatidentify specification 110 and/or that identify a location associatedwith specification 110. File name 620 may include information thatidentifies a name for specification 110. Location ID 625 may includeinformation that identifies a location where specification 110 can bestored. Location ID 625 may include a file name, an address, a link,etc.

FIG. 6B illustrates an exemplary API 601 that can be used withconfiguration 170 in an exemplary embodiment. In one implementation, API601 may include an input portion 603 and an output portion 604. Inputportion 603 may include user inputs 630, file ID 635, and configurationname 640.

User inputs 630 may include information received from a user. Forexample, a user may enter information about a configuration that shouldbe used with code generator 120 to generate code for target 150. File ID635 may include information that identifies a file that can containinformation used to create configuration 170. Configuration name 640 mayinclude information that identifies a particular implementation ofconfiguration 170. For example, configuration ID 640 may include a filename, address, etc., for configuration 170.

Output portion 604 may include destination ID 645 and configuration 650.Destination ID 645 may include information that identifies a device,application, etc., that receives configuration 170. For example,destination ID 645 may include a name, address, etc., of code generator120. Configuration information 650 may include data and instructions inconfiguration 170 that code generator 120 may need when generating codeusing specification 110. For example, configuration information 650 mayinclude information in user inputs 630 and information retrieved from afile identified by file ID 635.

FIG. 6C illustrates an exemplary API 602 that can be used to interactwith code generator 120 in an exemplary embodiment. API 602 may includean input portion 603 that can include specification ID 655,configuration ID 660, and user instruction 665. Specification ID 655 mayinclude information that identifies a specification 110 that can be sentto code generator 120. Configuration ID 660 may identify a configuration170 that is used with code generator 120. User instruction 665 mayinclude information input by a user for use with code generator 120. Forexample, user instruction 665 may include an instruction to start codegeneration.

Output portion 604 may include target information 670, constraints ID675, generated code ID 680, reporting 685, and error handling 690.Target information 670 may include information that identifies a targetdevice on which generated code 130 is configured to run. Constraints ID675 may include information that identifies constraints 140, whereconstraints 140 is related to generated code 130. Constraints ID 675 mayinclude an identifier for a file that includes constraints 140 (e.g., afile name, address, pointer, link, etc.), the actual contents ofconstraints 140, etc.

Generated code ID 680 may include information that identifies generatedcode 130. Embodiments of generated code ID 680 may include an identifierfor a file that includes generated code 130 or may include generatedcode 130 itself. Reporting 685 may include information related to targetinformation 670, constraints ID 675, generated code ID 680, theoperation of code generator 120, etc. For example, reporting 685 caninclude status information that is displayed to a user, sent to adevice, written to a file, etc., where the status information identifieswhether code generator 120 operated in a determined manner whenproducing generating code 130. Error handling 690 may includeinformation that identifies an error associated with code generator 120,such as an error produced when code generator 120 improperly producesgenerated code 130 or constraints 140.

APIs 600, 601 and 602 are exemplary and alternative embodiments ofsystem 100 or 105 may include more APIs, fewer APIs, or APIs inconfigurations that differ from those of FIGS. 6A-6C. In addition, APIs600, 601 and 602 used with exemplary embodiments may include morefields, fewer fields, or fields arranged in orders that differ from theordering of fields in FIGS. 6A-6C. APIs 600, 601 and 602 may operate asunified APIs

Exemplary User Interfaces

FIG. 7A illustrates an exemplary user interface that can be used toconfigure an exemplary embodiment. Interface 700 and/or other interfacesdescribed herein may be a graphical user interface (GUI) or anon-graphical user interface, such as a text based interface. Userinterface 700 and/or other user interfaces described herein may furtherprovide information to users via customized interfaces (e.g.,proprietary interfaces) and/or interfaces that are generally known tothose of skill in the art (e.g., browser-based interfaces).

User interfaces described herein, may receive user inputs via inputdevices, such as but not limited to, keyboards, pointing devices (e.g.,a mouse, stylus, trackball, touchpad, joystick, other types of motiontracking devices, etc.), biometric input devices, touch sensitivedisplays, microphones, etc. User interfaces described herein may be userconfigurable (e.g., a user may change the size of the user interface,information displayed in a user interface, color schemes used by theuser interface, positions of text, images, icons, windows, etc., in theuser interface, etc.) and/or may not be user configurable.

Interface 700 may be displayed to a user via an output device and mayinclude menu 705, display area 710, information window 715, fields 720,and cursor 725. Menu 705 may include information associated with menusthat are accessed by the user. For example, in one embodiment, menu 705my identify items, such as File, Edit, View, etc., that can be selectedby a user (e.g., via cursor 725) to open one or more drop down menus.Drop down menus may provide the user with substantially any number ofitems that can be selected by the user to invoke various types offunctionality on the user's behalf. For example, selecting File may opena drop down menu that includes Open, Close, Save, Save As, Print, PrintPreview, etc. Interface 700 may further include icons that let the userperform actions, such as moving to a previous display, returning to ahome display (or page), printing the contents of a portion of interface700, etc.

Display area 710 may include a portion of interface 700. For example,display area 710 may include a portion of interface 700 that is locatedbelow menu 705. Display area 710 may, or may not, be defined by a border(e.g., a boundary). Information window 715 may occupy a portion ofdisplay area 710 that is used to display information to a user, such asinformation related to specification 110, code generator 120, generatedcode 130, constraints 140, etc.

Fields 720 may include information related to generating code. Forexample, fields 720 may display information that allows a user to selectwhether generated code should be documented. For example, an executablefile, such as constraints 140, may be generated when a user indicatesthat generated code should be documented. In contrast, constraints 140may not be generated when the user indicates that generated code shouldnot be documented. Fields 720 may further include information about aninput file name, such as a name for an input file to code generator 120.Fields 720 may also include a file name for generated code, a name for aconstraint file, a name for generated code that includes constraintinformation embedded in the code (instrumented code), a file name forun-instrumented generated code, and a name for a checklist or a report.For example, code generator 120 can generate a checklist based on a userinput.

Cursor 725 may include a mechanism that can be positioned by a user ordevice to identify information in interface 700. Cursor 725 may bepositioned within interface 700 via a pointing device, a spoken command,a keyboard input, etc.

FIG. 7B illustrates an exemplary user interface 702 that can be used todisplay information about generated code in an exemplary embodiment.Interface 702 may be similar to interface 700 and may include reportname 730, send button 735, and report window 740. Report name 730 mayinclude information that identifies a report that includes informationabout generated code 130. In one embodiment, the report may beconstraints 140 and in another embodiment the report may be a documentthat includes information about generated code 130, constraints 140,specification 110 and/or configuration 170. Embodiments of the reportmay be in human-readable or machine-readable forms.

Send button 735 may allow a user to send information to a destination,such as a destination associated with an auditor. For example, codegenerator 120 may generate code for an application that needs to meetgovernment certification, such as a safety critical certification. Codegenerator 120 may generate an executable document, e.g., constraints140, and a separate, non-executable, report that details generated code130 (e.g., the report may identify optimizations that were made, mayinclude validation information about the optimizations, etc.). Selecting“Y” for send button 735 may send the report to the government auditor.

Report window 740 may include information in a report identified inreport name 730. For example, report window 740 may include informationabout assumptions made with respect to generated code 130, assertions ingenerated code 130, optimizations in generated code 130, safeguards thatmay have been turned off or turned on in generated code 130, sizeinformation about generated code 130, etc. In one embodiment, the reportcan also include a listing of generated code 130, e.g., a source codelisting.

FIG. 7C illustrates an exemplary user interface that can display areport 740 related to generated code. Report 740 may be displayed to auser via a display device, printed to hardcopy, or stored in acomputer-readable medium. In one embodiment, report 740 may includeinformation in constraints 140, and in another embodiment, report 740may be produced along with constraints 140. Report 740 may includeinformation about assumptions made in generated code 130, optimizationsmade in generated code 130, safeguards that may have been turned on orturned off when producing generated code 130, information aboutadditional reports, etc. Other embodiments of report 740 may includeother types of information. For example, an alternative embodiment ofreport 740 may include a checklist that can be completed by a userand/or a device.

Exemplary Processing

FIGS. 8A and 8B illustrate a flow chart showing exemplary processingthat can be used with an exemplary embodiment. The acts discussed inconnection with FIGS. 8A and 8B are illustrative. Other implementationsmay include more acts, fewer acts, or acts illustrated in FIGS. 8A and8B in an order that differs from the ordering shown in FIGS. 8A and 8B.

A user may generate specification 110 using, for example, a graphicalmodeling application. In one embodiment, the graphical model may begenerated in response to objectives (e.g., design objectives) and/orassumptions (e.g., assumptions about a device on which code generatedfrom the model will be run). In one embodiment, assumptions may be userdefined or tool defined (e.g., tooling assumptions). An environmentrunning the graphical model may transform the objectives and/orassumptions into assertions.

A computing device may host code generator 120 and/or other applications(e.g., the graphical modeling application). The computing device mayreceive specification 110 (act 805). The computing device may furtherreceive configuration 170 (act 810). For example, a user or a device maygenerate a configuration file that will be used when code is generatedbased on specification 110. The configuration file may includeinformation that is used to configure hardware and/or software usedduring code generation. For example, the configuration file may includeinformation about initializing a memory, about integer widths, overflowhandling, etc.

The computing device may generate code and a constraints document basedon specification 110 and configuration 170 (act 815). For example, codegenerator 120 may produce generated code 130 and constraints 140.Generated code 130 may be produced in substantially any format. Forexample, code generator 120 may produce source code, such as C sourcecode (e.g., .h files, include files, etc.), C++ source code, make files,Perl code, Java code, etc. In an alternative embodiment, code generator120 may produce compiled code, such as code in .dll files, .ASM files,etc. In one embodiment, code generator 120 may generate code that canwork with another type of code. For example, code generator 120 maygenerate C source code that uses an integer representation of 16 bits.The generated C code may be operated on by Perl code that changes the 16bit integer representation to a 32 bit integer representation, where the32 bit representation is compatible with target 150.

Code generator 120 may automatically generate constraints 140 to captureassumptions in a form that can be validated against requirements and/orobjectives. For example, information in constraints 140 may identify anexisting hardware environment, software environment, etc., and mayfurther include information that allows the hardware/softwareenvironment to be reestablished at a later time without requiring thatcode generator 120 regenerate code. Information in constraints 140 mayact as diagnostic code that allows constraints imposed by generated code130 to be validated when constraints 140 is executed. For example,constraints 140 can include code that identifies optimizations made bycode generator 120 during code generation.

Constraints 140 may link assertions to features and/or optimizations ingenerated code. Constraints 140 may further link assertions, featuresand/or optimizations with requirements and/or objectives, which allowsassertions, features, and/or optimizations to be traced back to therequirements and/or objectives. As a result, generated code 130 can bevalidated using exemplary embodiments described herein. For example,code generator 120 may generate intermediate representations whengenerating code. Code generator 120 may further perform optimizationsbased on requirements, information in configuration 170, etc.Constraints 140 may capture information (e.g., constraints) at eachintermediate representation and/or whenever an optimization isperformed. Information in constraints 140 may allow a user and/or deviceto determine where intermediate transformations occurred in generatedcode 130, where and/or why optimizations were performed, etc.Information in constraints 140 may allow accurate identification of anon-adhering constraint, as might occur when a constraint is not adheredto in generated code 130.

Constraints 140 may also include information about code coverage. Forexample, constraints 140 may include information generated from ananalysis performed on generated code 130, where the analysis determineswhether portions of generated code 130 are exercised when generated code130 is run. Constraints 140 may also include other types of information,such as information used for a checklist or a report. For example,constraints 140 can generate a checklist that can be printed and/or usedby an operator to determine whether generated code 130 meets determinedcriteria when run on target 150 or new target 190. A report may begenerated according to a determined format, such as a governmentmandated reporting format. Constraints 140 may populate the report withinformation, or a user can manually enter information into the report.In one embodiment, constraints 140 may send the report to a destination.

Embodiments of code generator 120 can create instrumented code (e.g.,code that includes executable information from constraints 140 withingenerated code 130) or un-instrumented code (e.g., by producinggenerated code 130 and a separate executable constraints 140 document,file, object, etc.). Code generator 120 may further produce an emulatorthat can be used to run un-instrumented code or instrumented code on newtarget 190 and/or another device.

Referring now to FIG. 8B, a determination may be made as to whethergenerated code 130 should be run on target 150 (act 820). Constraintchecker 180 may optionally be run (block 825) when generated code willbe run on target 150. For example, in one embodiment it may be desirableto run constraint checker 180 to analyze generated code 130 to determinethat generated code 130 will operate in a determined manner on target150 (e.g., by achieving a desired code coverage goal). Constraintchecker 180 may also be run to perform other functions, such as toexplicitly state constraints (e.g., to state constraints in a report).In another embodiment, a determination may be made that constraintchecker 180 should not be run since generated code 130 was designed torun on target 150, and, therefore, constraint checking 165 may beunnecessary.

Generated code 130 may be sent to target 150 (act 830). For example,generated code 130 may be sent over a link (wired or wireless) to target150. Target 150 may run generated code 130 to perform one or moredetermined operations, such as useful and/or tangible operations (act835). For example, generated code 130 may be used to control a device(e.g., a robotic arm), to display information to a user, to storeinformation in a storage device, to perform computations that generate aresult, etc.

Returning to act 820, a determination may be made that generated code130 should not be run on target 150. When this determination is made atact 820, processing may move to act 840. For example, a determinationmay be made as to whether generated code 130 should be run on new target190 (act 840). Constraint checker 180 may be run on generated code 130before generated code 130 is run on new target 190 (act 845). Constraintchecker 180 may determine whether optimizations are valid on new target190, whether assertions are valid on new target 190, whether desiredcode coverage is achieved when generated code 130 is run on new target190, etc.

For example, constraint checker 180 may execute constraints 140 todetermine that certain data (such as input data) is out of bounds whengenerated code 130 is run on new target 190 because new target 190 mayhave an input saturation that is lower than an input saturation fortarget 150. Constraint checker 180 may flag the data as being out ofbounds and may identify a portion of generated code 130 that operates onthe input data. Constraint checker 180 may further identify whetheroptimizations were made with respect to code that pertains to the inputdata. For example, constraint checker 180 may produce a message thatexplains the type of optimization that was made, identifies assumptionsrelated to the optimization, provides non-optimized code that can beused to replace the optimized code, etc. In one embodiment, constraintchecker 180 may complete a checklist on behalf of an operator to let theoperator know whether generated code 130 will operate in a determinedmanner on new target 190. In another embodiment, constraint checker 180may map optimizations, assumptions, etc., back to a source document(e.g., specification 110) using executable information in constraints140.

Generated code 130 may be sent to new target 190 when constraint checker180 determines that generated code 130 will operate in a determinedmanner (act 850). In one embodiment, act 850 may occur before act 845and constraint checker 180 may be run on new target 190 when generatedcode 130 is received thereon.

Generated code 130 may be run on new target 190 to perform an operation(act 855). For example, target 150 may be a defibrillator that was builtin 2005 and generated code 130 may run the defibrillator in a determinedmanner when installed thereon. Generated code 130 may be installed ontonew target 190 in act 850, which may be a newer model of thedefibrillator (e.g., a model built in 2006). Generated code 130, oncevalidated, may perform the same operations on new target 190 (in act855) that correspond to operations performed on target 150 whengenerated code 130 was previously run thereon.

Exemplary Device Architecture

FIG. 9 illustrates an exemplary architecture for implementing exemplaryembodiments on a computing device. As illustrated in FIG. 9, computer900 may include a bus 910, a processor 920, a memory 930, a read onlymemory (ROM) 940, a storage device 950, an input device 960, an outputdevice 970, and a communication interface 980.

Bus 910 may include one or more interconnects that permit communicationamong the components of computer 900. Processor 920 may include any typeof processor, microprocessor, or processing logic that may interpret andexecute instructions (e.g., an FPGA). Processor 920 may include a singledevice (e.g., a single core) and/or a group of devices (e.g.,multi-core). Memory 930 may include a random access memory (RAM) oranother type of dynamic storage device that may store information andinstructions for execution by processor 920. Memory 930 may also be usedto store temporary variables or other intermediate information duringexecution of instructions by processor 920.

ROM 940 may include a ROM device and/or another type of static storagedevice that may store static information and instructions for processor920. Storage device 950 may include a magnetic disk and/or optical diskand its corresponding drive for storing information and/or instructions.

Input device 960 may include any mechanism or combination of mechanismsthat permit an operator to input information to computer 900, such as akeyboard, a mouse, a touch sensitive display device, a microphone, apen-based pointing device, and/or a biometric input device, such as avoice recognition device and/or a finger print scanning device. Outputdevice 970 may include any mechanism or combination of mechanisms thatoutputs information to the operator, including a display, a printer, aspeaker, etc.

Communication interface 980 may include any transceiver-like mechanismthat enables computer 900 to communicate with other devices and/orsystems, such as target 150, new target 190, etc. For example,communication interface 980 may include one or more interfaces, such asa first interface coupled to a network and/or a second interface coupledto another device, such as a network device (e.g., router, firewall,switch, gateway, etc.). Alternatively, communication interface 980 mayinclude other mechanisms (e.g., a wireless interface) for communicatingvia a network, such as a wireless network. Tn one implementation,communication interface 980 may include logic to send code to adestination device, such as a target device that can include generalpurpose hardware (e.g., a personal computer form factor), dedicatedhardware (e.g., a digital signal processing (DSP) device adapted toexecute a compiled version of a model or a part of a model), etc.

Computer 900 may perform certain functions in response to processor 920executing software instructions contained in a computer-readable medium,such as memory 930. A computer-readable medium may be defined as one ormore memory devices and/or carrier waves. In alternative embodiments,hardwired circuitry may be used in place of or in combination withsoftware instructions to implement features consistent with principlesof the invention. Thus, implementations consistent with principles ofthe invention are not limited to any specific combination of hardwarecircuitry and software.

Exemplary Networked Embodiment

FIG. 10 illustrates an exemplary system 1000 that can be used togenerate code in a networked environment. System 1000 may include target150, new target 190, computer 900, network 1020, and service provider1030. The embodiment of FIG. 10 is illustrative and other embodimentscan include additional devices, fewer devices, or devices inarrangements that differ from the arrangement of FIG. 10.

Computer 900 may include a device capable of sending data to orreceiving data from another device, such as target device 150. “Data,”as used herein, may refer to any type of machine-readable informationhaving substantially any format that may be adapted for use in one ormore networks and/or with one or more devices. Data may include digitalinformation or analog information. Data may further be packetized and/ornon-packetized.

Computer 900 may be a computer, such as a desktop computer, a laptopcomputer, a client, a server, a mainframe, a personal digital assistant(PDA), a web-enabled cellular telephone, a smart phone, smartsensor/actuator, or another computation or communication device thatexecutes instructions to perform one or more activities and/or generateone or more results.

In one embodiment, computer 900 may include code generator 120,configuration 170, and technical computing environment (TCE) 1010. Inother embodiments, computer 900 may include other components,applications, etc. (e.g., peripheral devices, etc.).

TCE 1010 may include hardware and/or software based logic that providesa computing environment that allows users to perform tasks related todisciplines, such as, but not limited to, mathematics, science,engineering, medicine, business, etc., more efficiently than if thetasks were performed in another type of computing environment, such asan environment that required the user to develop code in a conventionalprogramming language such as C++, C, Fortran, Pascal, etc.

In one implementation, TCE 1010 may include a dynamically typed languagethat can be used to express problems and/or solutions in mathematicalnotations familiar to those of skill in the relevant arts. For example,TCE 1010 may use an array as a basic element, where the array may notrequire dimensioning. In addition, TCE 1010 may be adapted to performmatrix and/or vector formulations that can be used for data analysis,data visualization, application development, simulation, modeling,algorithm development, etc. These matrix and/or vector formulations maybe used in many areas, such as statistics, image processing, signalprocessing, control design, life sciences modeling, discrete eventanalysis and design, state based analysis and design, etc.

TCE 1010 may further provide mathematical functions and/or graphicaltools (e.g., for creating plots, surfaces, images, volumetricrepresentations, etc.). In one implementation, TCE 1010 may providethese functions and/or tools using toolboxes (e.g., toolboxes for signalprocessing, image processing, data plotting, distributed processing,etc.). In another implementation, TCE 1010 may provide these functionsas block sets. In still another implementation, TCE 1010 may providethese functions in another way, such as via a library, etc. TCE 1010 maybe implemented as a text based environment, a graphically basedenvironment, or another type of environment, such as a hybridenvironment that is both text and graphically based.

Network 1020 may include any network capable of transferring data (e.g.,packet data or non-packet data). Implementations of network 1020 mayinclude local area networks (LANs), metropolitan area networks (MANs)and/or wide area networks (WANs), such as the Internet, that may operateusing substantially any network protocol, such as Internet protocol(IP), asynchronous transfer mode (ATM), synchronous optical network(SONET), user datagram protocol (UDP), IEEE 802.11, etc.

Network 1020 may include network devices, such as routers, switches,firewalls, and/or servers (not shown). Network 1020 may be a hardwirednetwork using wired conductors and/or optical fibers and/or may be awireless network using free-space optical, radio frequency (RF), and/oracoustic transmission paths. In one implementation, network 1020 may bea substantially open public network, such as the Internet. In anotherimplementation, network 1020 may be a more restricted network, such as acorporate virtual network. Implementations of networks and/or devicesoperating on networks described herein are not limited to any particulardata type, protocol, architecture/configuration, etc.

Service provider 1030 may include logic that makes a service availableto another device on network 1020. For example, a service provider 1030may include a server operated by an entity (e.g., an individual, acorporation, an educational institution, a government agency, etc.) thatprovides one or more services to a destination, such as computer 900.Services may include instructions that are executed by a destination toallow the destination to perform an operation, or instructions that maybe executed on behalf of the destination or to perform an operation onthe destination's behalf.

Assume, for sake of example, that a corporation operates a web serverthat provides one or more web-based services to a destination. Theweb-based services may allow the destination (e.g., a computer operatedby a customer) to generate constraints 140 for generated code 130. Forexample, the customer may be able to generate undocumented code usingcode generator 120 when the customer does not subscribe to a service. Incontrast, the customer may be able to generate documented code (e.g.,may be able to produce generated code 130 and constraints 140) when thecustomer subscribes to the service. The service may further provideadditional capabilities to the customer, such as by providing constraintchecking services that can be used to validate generated code 130 on newtarget 190, report generating capabilities that allow the customer togenerate reports according to determined formats, audit services thatallow a customer's code to be audited, etc.

In one implementation, service provider 1030 may provide services to thecustomer on a subscription basis. A subscription may includesubstantially any type of arrangement, such as monthly subscription, aper-use fee, a fee based on an amount of information exchanged betweenthe provider and the customer, a fee based on a number of processorcycles used by the customer, etc.

Illustrative Embodiments

Two illustrative embodiments will be described in connection with FIGS.11-19 to further illustrate uses for exemplary embodiments. In a firstillustrative embodiment, an application may explicitly initialize allglobal memory used by generated code. For example, a product, such asReal-Time Workshop Embedded Coder (RTW EC) by The MathWorks of NatickMass., may have a default mode that initializes global memory used bygenerated code. Certain implementations may include logic that setsglobal memory to zero. RTW EC may include user configurable options thateliminate global memory zero initialization so as to avoid thedisadvantages of zero initializing global memory (e.g., zeroinitializing global memory may be expensive with respect to ROM usage).For example, RTW EC may not zero initialize global memory because adevice may zero global memory during its boot process. Re-zeroing globalmemory in this instance using RTW EC may be redundant.

A user may interact with a GUI to select optimizations, such as globalmemory initialization. For example, the user may be presented with GUI1100 as illustrated in FIG. 11. GUI 1100 may let the user check oruncheck boxes using a pointing device, such as cursor 725. GUI 1100 mayfurther let the user enter alphanumeric information via an input device,such as a keyboard. The user may select remove root level I/O zeroinitialization 1110 or remove internal state zero initialization 1120(as evidenced by the lack of a check mark in the corresponding boxes for1110 and 1120). The user may select OK when the user is satisfied withhis/her selections.

The user may interact with GUI 1100 on behalf of a model, such as agraphical model, from which the user will generate code, such as C, C++,etc., code. For example, GUI 1100 may be associated with model 1200illustrated in FIG. 12, where model 1200 is a graphical model of aphysical system. In one embodiment, graphical model 1200 may bedisplayed on output device 970, which may be an LCD display. Model 1200may include a model region 1210 in which blocks, or other graphicalrepresentations, are displayed.

The user may generate code from model 1200. For example, generated code1300, illustrated in FIG. 13, may be generated from model 1200 based ona user input. In one embodiment, generated code 1300 may include anumber of data structures, such as a block signals data structure, ablock states data structure, etc.

Since the device on which generated code 1300 is run performs globalmemory initialization at boot time, generated code 1300 may be optimizedby omitting, or turning off, logic in the generated code that wouldotherwise perform global memory initialization (e.g., logic associatedwith 1110 and 1120 of FIG. 11). For example, initialization code that isgenerated using RTW EC and that includes the optimization may begenerated code 1400, which is illustrated in FIG. 14.

In an alternative embodiment, logic that initializes global memory maynot be turned off, or omitted, when the user interacts with the RTW ECGUI. For example, FIG. 15 illustrates GUI 1500 which is substantiallyidentical to GUI 1100 except that the check boxes associated with 1110and 1120 are not checked (as evidenced by the empty check boxes for 1110and 1120). Root level I/O zero initialization (1110) and internal statezero initialization (1120) code will not be removed from code generatedusing GUI 1500. The user may select OK when the user is satisfied withhis/her selections in FIG. 15.

The user may generate code that includes additional code forinitialization, namely root level I/O zero initialization and internalstate zero initialization. FIG. 16 illustrates file 1600 that includescode generated using GUI 1500.

The exemplary embodiment of FIG. 15 may generate an independentexecutable file that can be used to self-diagnose generated code in file1600. For example, file 1700, illustrated in FIG. 17, may includediagnostic code that can be used to validate an assumption used by acode generator when file 1600 was generated. For example, file 1700identifies the assertion that the code generator made regarding theoptimization for initializing memory. The user can call file 1700 priorto calling the initialization core to validate that the user hasdeployed generated code consistent with assumptions made by the user andlater used by the code generator to generate code. Embodiments of file1700 can dynamically validate generated code in file 1600 at runtime. Inan alternative embodiment, file 1700 may statically validate generatedcode 130.

A second illustrative example, may include self-diagnostic code thatvalidates sample time properties in generated code. For example, sampletimes associated with a graphical model, such as model 1200 may beimplemented in generated code. For example, a step function in the modelmay be called once per second. A user may interact with a GUI, such asGUI 1800 in FIG. 18, to enter model parameters, such as the stepfunction sample rate of 1 second. The user may select OK when he/she issatisfied with the parameters in GUI 1800.

The user may generate code for model 1200 using a code generator, suchas RTW EC. The code generator may generate a file containing thegenerated code and a separate file containing self-diagnostic code. Forexample, RTW EC may generate file 1900 that includes a self-diagnosticfunction that validates the assumption made by the code generator withrespect to the step function sample rate. The user may call file 1900 tovalidate generated code that includes the step function and/or thesample rate. For example, the code generator assumed that the stepfunction code is executed once per second. The user can call file 1900with each invocation of the step function in model 1200 to validate thatthe user has deployed generated code consistent with assumptions made bythe code generator.

Exemplary Alternative Embodiments

Many alternative embodiments are possible based on the foregoingdescription. For example, a first alternative embodiment may generateconstraints 140 when producing generated code 130, where constraints 140includes a report. For example, system 100 may include a reportgenerator that includes a number of report generating components thatare used to generate reports according to one or more templates. Forexample, an operator may indicate that constraints 140 should includeinformation that identifies hot spots in generated code and a degree ofconfidence indicator for each hot spot that indicates a likelihood thata hot spot will not invalidate generated code. Code generator 120 maycall the report generator when generating constraints 140. The reportgenerator may use a hot spot component to collect and format the hotspot information, a confidence indicator component to compute anddisplay confidence information, and a formatting component to format thereport according to operator determined parameters.

A second alternative embodiment may generate a constraints document inwhich the content or format of a document portion varies based on theimportance of a portion of generated code to which the document portionpertains. For example, generated code 130 may include a first portionthat is critical to proper operation of target 150 and a second portionthat is not critical to operation of target 150 (e.g., the secondportion may control the contrast of a display). Constraints 140 mayinclude a first document portion related to the first code portion and asecond document portion related to the second code portion. Inconstraints 140, the first document portion may include highly detailedinformation about assertions, optimizations, etc., related to the firstcode portion. In addition, the first document portion may include linksbetween all requirements in a specification and corresponding portionsof generated code. In contrast, the second document portion may includeover view information about the second code portion since the secondcode portion is not critical to the operation of target device 150.

A third alternative embodiment may include code generator 120 that mayconvert certain blocks associated with specification 110 into assertionsand/or diagnostics. For example, a graphical model may use a blocklibrary that includes a first block that is converted to an assertion bycode generator 120 and a second block that is used to identify adiagnostic function in generated code 130. Code generator 120 may createan assertion in generated code 130 based on the first block and mayinsert the diagnostic function into generated code 130 based on thesecond block.

A fourth alternative embodiment may implement TCE 1010 using one or moretext-based products. For example, a text-based TCE 1010, may beimplemented using products such as, but not limited to, MATLAB® by TheMathWorks, Inc.; Octave; Python; Comsol Script; MATRIXx from NationalInstruments; Mathematica from Wolfram Research, Inc.; Mathcad fromMathsoft Engineering & Education Inc.; Maple from Maplesoft; Scilab fromThe French Institution for Research in Computer Science and Control(INRIA); or Modelica or Dymola from Dynasim. The text-based TCE maysupport one or more commands that support code generation, constraintsgeneration, constraints checking, etc.

A fifth alternative embodiment may implement TCE 1010 in agraphically-based TCE 1010 using products such as, but not limited to,Simulink®, Stateflow®, SimEvents™, etc., by The MathWorks, Inc.; VisSimby Visual Solutions; LabView® by National Instruments; Dymola byDynasim; Extend from Imagine That Inc.; SoftWIRE by MeasurementComputing; WiT by DALSA Coreco; VEE Pro or SystemVue by Agilent; SystemVIEW from Elanix, Vision Program Manager from PPT Vision, Khoros fromKhoral Research, Gedae by Gedae, Inc.; Scicos from (INRIA); Virtuosofrom Cadence, Rational Rose from IBM, Rhopsody or Tau from Telelogic; oraspects of a Unified Modeling Language (UML) or SysML environment. Thegraphically-based TCE may support code generation, constraintsgeneration, constraints checking, etc.

A sixth alternative embodiment may be implemented in a language that iscompatible with a product that includes a TCE, such as one or more ofthe above identified text-based or graphically-based TCE's. For example,MATLAB (a text-based TCE) may use a first command to represent an arrayof data and a second command to transpose the array. Another TCE may beMATLAB-compatible and may be able to use the array command, the arraytranspose command, or other MATLAB commands. For example, the languagemay use the MATLAB commands to perform distributed processing usingtarget 150 and/or 190.

A seventh alternative embodiment may be implemented in a hybrid TCE thatcombines features of a text-based and graphically-based TCE. In oneimplementation, one TCE may operate on top of the other TCE. Forexample, a text-based TCE (e.g., MATLAB) may operate as a foundation anda graphically-based TCE (e.g., Simulink) may operate on top of MATLABand may take advantage of text-based features (e.g., commands) toprovide a user with a graphical user interface and graphical outputs(e.g., graphical displays for data, dashboards to monitor performance ofgenerated code 130, etc.).

An eighth alternative embodiment, a TCE, such as MATLAB, may storeconstraints in a file, such as a .mat, file when code is generated bycode generator 120. The embodiment may use the .mat file to documentgenerated code 130 or may convert the .mat file into another format,such as a format used by new target device 190. The embodiment may usean API to access information stored in the .mat file (e.g., to accessheader information, tags, data, etc.) and to write the accessedinformation out in a format that differs from the input format. Forexample, the embodiment may convert the .mat format into a .xml format.The API may read the .mat file, transform the information into an outputformat, and may output the transformed information into a file.Alternatively, the API may read the .mat file and may send theinformation to transforming logic (e.g., transforming code) where thetransforming logic converts the .mat format into the .xml format.Embodiments, such as the eighth alternative embodiment, may storeconstraints in machine-readable formats that can be used by one or moredevices. For example, constraints can be stored via an object in a TCEclass.

A ninth alternative embodiment may generate real-time executable codethat may include data structures and/or functions. Constraints 140 maybe produced when the real-time executable code is generated by codegenerator 120 and may include information about an application componentand a run-time interface component in the generated code. Theapplication component may implement data and/or functions (e.g.,data/functions implemented via blocks in a block diagram). The run-timeinterface component may be used for managing and/or supporting executionof the executable code on a target device, such as target 150 and/or190. Constraints 140 may include information for the run-time interfacecomponent (e.g., a main program) that initializes data structures,installs and/or implements interrupt service routines, executesbackground loops, performs cleanup operations, etc. Information inconstraints 140 may allow identification of portions of the applicationcomponent and/or the run-time interface component (e.g., criticalportions) in a way that lets a user quickly and/or accurate locateand/or diagnose code associated with the real-time executable code.

A tenth alternative embodiment may include a constraints document thatcan be in a human-readable or machine-readable format and that caninclude information about reentrant code (e.g., a reentrant function)and/or non-reentrant code (e.g., a non-reentrant function). Theconstraints document may include information that identifies whether apiece of code is reentrant or non-reentrant (e.g., by containing a flagwith a first value for reentrant code and a second value fornon-reentrant code). The constraints document may further includeinformation that identifies how reentrant or non-reentrant code behaves(e.g., the constraints document may include information that indicatesthat the reentrant code should not modify a global variable, that inputsand/or outputs should be passed via arguments and/or return values,etc.). The constraints document may further include information thatidentifies code types based on a likelihood that the code may notoperate in a determined manner. For example, it may be more difficultfor a user to determine whether non-reentrant code operates in a desiredmanner when the non-reentrant code is contained in generated code. Theconstraints document may insert an indicator (e.g., a symbol) into ahuman-readable version of the constraints document to draw a user'sattention to a piece of non-reentrant code (e.g., a non-reentrantfunction) so that the user is more likely to perform a carefulevaluation of the non-reentrant code. The constraints document mayfurther include information that can be used to test the reentrant codeand/or non-reentrant code when desired.

An eleventh alternative embodiment may include a code generator that canreceive constraints and/or assumptions from a specification, that canreceive constraints and/or assumptions from a user, and that cangenerate its own constraints and/or assumptions. For example, the codegenerator may, or may not, generate its own constraints and/orassumptions when generating code on behalf of a user. These constraintsmay be incorporated into a constraints document alone or along withconstraints and/or assumptions from the user and/or specification. Forexample, in one alternative embodiment, the code generator may generateconstraints and/or assumptions that can operate with a scheduler thatdiffers from a scheduler associated with a target device. For example,the code generator may operate with a first scheduler (e.g., arate-monotonic scheduler, earliest deadline first scheduler, etc.) thatoperates with a current target device. The code generator may generateconstraints and/or assumptions for the first scheduler. A later versionof the code generator may generate code that can be used with adifferent scheduler. The earlier constraints document may be used toindicate that the earlier generated code can be used with the differentscheduler when the different scheduler is, for example, a rate-monotonicscheduler.

A twelfth alternative embodiment may monitor thread safety in generatedcode. For example, generated code 130 may include a number of threadsthat run at the same time when generated code 130 is executed. Forexample, generated code 130 may control a number of processes where eachprocess is associated with one or more threads. Further assume that thethreads are supposed to operate independently (i.e., without interactingwith other threads simultaneously running). The threads may operatecorrectly on target 150; however, a user may need to port generated code130 to new target 190 where correct thread operation may not yet beknown. Constraints 140 may include executable instructions thatdynamically determine whether the threads interact with each other whenrun on new target 190. For example, the user may run constraint checker180 and constraints 140 may be executed. Logic in constraints 140 maydetermine that none of the threads interact with each other whengenerated code 130 is run on target 190. Constraints 140 may generate areport for the user that indicates that all threads will operate in adesired manner on new target 190.

A thirteenth alternative embodiment may document generated code that isassociated with industry specific or open source initiatives. Forexample, unified modeling language (UML) is a standardized specificationlanguage for object modeling. UML allows users to create abstract modelsof systems (such as software based systems). System modeling language(SysML) is a domain specific modeling language used in systemsengineering and can support the specification, analysis, design,verification and validation of systems. Automotive open systemarchitecture (AUTOSAR) is an open and standardized automotive softwarearchitecture jointly developed by automobile manufacturers, suppliers,and tool developers. AUTOSAR can serve as a platform on which futurevehicle applications can be designed and/or implemented. UML, SysML,AUTOSAR, and other similar applications, can include electronicinformation (e.g., models, specifications, electronic documents,instructions, etc.). At times, it may be beneficial to generate codefrom UML, SysML, AUTOSAR, etc., compatible information. Exemplaryembodiments can generate an executable document or a document that ispartially executable that captures information about UML, SysML,AUTOSAR, etc., compatible information. Theexecutable/partially-executable document can be used to validateinformation related to UML, SysML, AUTOSAR, etc., such as information ingenerated code.

Still other alternative implementations are possible consistent with thespirit of the invention.

CONCLUSION

Implementations may provide devices and techniques that documentgenerated code.

The foregoing description of exemplary embodiments of the inventionprovides illustration and description, but is not intended to beexhaustive or to limit the invention to the precise form disclosed.Modifications and variations are possible in light of the aboveteachings or may be acquired from practice of the invention. Forexample, while a series of acts has been described with regard to FIGS.8A and 8B, the order of the acts may be modified in otherimplementations consistent with the principles of the invention.Further, non-dependent acts may be performed in parallel.

In addition, implementations consistent with principles of the inventioncan be implemented using devices and configurations other than thoseillustrated in the figures and described in the specification withoutdeparting from the spirit of the invention. Devices and/or componentsmay be added and/or removed from the implementations of FIGS. 1A, 1B, 2,3A, 3B, 4, 9, and 10 depending on specific deployments and/orapplications. Further, disclosed implementations may not be limited toany specific combination of hardware.

Further, certain portions of the invention may be implemented as “logic”that performs one or more functions. This logic may include hardware,such as hardwired logic, an application-specific integrated circuit, afield programmable gate array, a microprocessor, software, wetware, or acombination of hardware and software.

No element, act, or instruction used in the description of the inventionshould be construed as critical or essential to the invention unlessexplicitly described as such. Also, as used herein, the article “a” isintended to include one or more items. Where only one item is intended,the term “one” or similar language is used. Further, the phrase “basedon,” as used herein is intended to mean “based, at least in part, on”unless explicitly stated otherwise.

The scope of the invention is defined by the claims and theirequivalents.

What is claimed is:
 1. A non-transitory computer-readable medium storinginstructions, the instructions comprising: one or more instructionsthat, when executed by at least one processor, cause the at least oneprocessor to: document an assumption in connection with an optimizationmade during code generation that produces generated code; generate,based on the assumption, an executable constraints document, theexecutable constraints document being separate from the generated code,and the executable constraints document including: first informationabout the assumption, and second information about a target device onwhich the generated code will be run; and execute the constraintsdocument; determine, based on executing the constraints document, thatinput data is out of bounds when the generated code is run on the targetdevice; identify that the assumption is associated with the input databeing out of bounds; determine a validation result for the optimizationbased on identifying the assumption; and perform an operation based onthe validation result, the operation including: providing the validationresult for display to a user, storing the validation result, sending thevalidation result to a destination, or modifying the generated code. 2.The non-transitory computer-readable medium of claim 1, where theoptimization is related to an operation associated with a safetycritical application.
 3. The non-transitory computer-readable medium ofclaim 1, where the assumption is related to a specification used forproducing the generated code.
 4. The non-transitory computer-readablemedium of claim 1, where the generated code is originally created for aprevious version of the target device that is different from a newversion of the target device.
 5. The non-transitory computer-readablemedium of claim 1, where the executable constraints document furtherincludes scheduling semantics and execution semantics.
 6. Thenon-transitory computer-readable medium of claim 1, where the generatedcode includes a reentrant function, and where the executable constraintsdocument further includes information that identifies the reentrantfunction.
 7. The non-transitory computer-readable medium of claim 6,where the executable constraints document further includes executablecode that tests the reentrant function.
 8. The non-transitorycomputer-readable medium of claim 1, where the generated code includes afunction having a formal argument or an actual argument.
 9. Thenon-transitory computer-readable medium of claim 8, where the executableconstraints document further includes third information that identifiesthe formal argument or the actual argument.
 10. The non-transitorycomputer-readable medium of claim 8, where the executable constraintsdocument further includes code that is used to test the function. 11.The non-transitory computer-readable medium of claim 1, where theexecutable constraints document further includes executable informationthat makes a determination with respect to interactions among threads inthe generated code.
 12. The non-transitory computer-readable medium ofclaim 1, where the optimization is validated at runtime.
 13. Thenon-transitory computer-readable medium of claim 1, where the one ormore instructions to determine the validation result further comprise:one or more instructions that, when executed by the at least oneprocessor, cause the at least one processor to: determine thread safetywith respect to one or more threads in the generated code, and determinethe validation result based on identifying the assumption and based ondetermining the thread safety.
 14. The medium of claim 1, where theexecutable constraints documents is one of an automotive open systemarchitecture (AUTOSAR) compatible document, a unified modeling language(UML) compatible document, or a system modeling language (SysML)compatible document.
 15. A method comprising: documenting an assumptionor an assertion made in connection with an optimization in generatedcode; generating a document based on the assumption or the assertion,generating the document being performed by a device, the document beingseparate from the generated code, and the document including: firstinformation about the assumption or the assertion, and secondinformation about a target device on which the generated code will berun; determining, based on the document, that input data is out ofbounds when the generated code is run on the target device, determiningthat the input data is out of bounds being performed by the device;identifying that the assumption or the assertion is associated with theinput data being out of bounds, identifying that the assumption or theassertion is associated with the input data being out of bounds beingperformed by the device; determining validation information, for atleast a portion of functional code in the generated code, based onidentifying that the assumption or the assertion is associated with theinput data being out of bounds, determining the validation informationbeing performed by the device; and performing an operation based on thevalidation information, performing the operation being performed by thedevice, and performing the operation including one or more of:providing, for display, the validation information to a user, storingthe validation information in a storage device, sending the validationinformation to a destination that performs another operation based onthe validation information, or modifying the generated code based on thevalidation information.
 16. A computing device comprising: a processorto: generate an executable document that maps an assumption to anassertion associated with generated code, the executable document beingseparate from the generated code, and the executable document including:first information about the assumption, and second information about atarget device on which the generated code will be run; determine, basedon the executable document, that input data is out of bounds when thegenerated code is run on the target device; identify that the assumptionor the assertion is associated with the input data being out of bounds;determine particular information regarding the generated code or theexecutable document based on identifying that the assumption or theassertion is associated with the input data being out of bounds; andperform an operation based on the particular information, whenperforming the operation, the processor is to one or more of: providethe particular information for display, store the particular informationin a storage device, send the particular information to a destinationthat performs another operation based on the particular information, ormodify the generated code based on the particular information.
 17. Thecomputing device of claim 16, where the processor is further to: operatea constraint checker on the generated code and on the executabledocument to validate the generated code, the particular informationregarding the generated code or the executable document being furtherbased on operating the constraint checker.
 18. The computing device ofclaim 16, where the processor is further to: generate a report or achecklist that includes information about the assumption or theassertion; and provide the report or the checklist.
 19. The computingdevice of claim 16, where the processor is further to: send thegenerated code or the executable document to the target device or toanother device.
 20. A non-transitory computer-readable medium storinginstructions, the instructions comprising: one or more instructionsthat, when executed by at least one computing device, cause the at leastone computing device to: receive a user input related to an assumptionregarding code, generate, based on the user input, an executableconstraints document, the executable constraint document being separatefrom the code, the executable constraint document mapping the assumptionto an assertion in the code, and the executable constraints documentincluding: first information about the assumption, and secondinformation about a target device on which the code will be run;determine, based on the executable constraints document, that input datais out of bounds when the code is run on the target device; identifythat the assumption is associated with the input data being out ofbounds; determine particular information about the code based on theuser input and based on identifying that the assumption is associatedwith the input data being out of bounds; and perform an operation basedon the particular information, the one or more instructions to performthe operation including: one or more instructions that, when executed bythe at least one computing device, cause the at least one computingdevice to one or more of: provide the particular information fordisplay, store the particular information in a storage device, send theparticular information to a destination that performs another operationbased on the particular information, or modify the code based on theparticular information.
 21. The non-transitory computer-readable mediumof claim 20, where the instructions further comprise: one or moreinstructions that, when executed by the at least one computing device,cause the at least computing device to: provide, for display in a userinterface, information in a specification associated with the code, aconfiguration file associated with the code, or the executableconstraints document.
 22. The non-transitory computer-readable medium ofclaim 20, where the particular information is displayed in a report or achecklist.
 23. The non-transitory computer-readable medium of claim 20,where the instructions further comprise: one or more instructions that,when executed by the at least one computing device, cause the at leastcomputing device to: receive, from a user, configuration information fora code generator that generates the code, and configure the codegenerator based on the configuration information.
 24. A systemcomprising: a processor to: document an assumption or an assertion madein connection with an optimization in generated code; generate anexecutable constraints document for the generated code, the executableconstraints document being separate from the generated code, and theexecutable constraints document including: first information about theassumption or the assertion, and second information about a targetdevice on which the generated code will be run; determine, based on theexecutable constraints document, that input data is out of bounds whenthe generated code is run on the target device; identify that theassumption or the assertion is associated with the input data being outof bounds; determine a validation result, for at least a portion of thegenerated code, based on identifying that the assumption or theassertion is associated with the input data being out of bounds; andperform an operation based on the validation result, and when performingthe operation, the processor is to one or more of: provide thevalidation result for display, store the validation result in a storagedevice, send the validation result to a destination that performsanother operation based on the validation result, or modify thegenerated code based on the validation result.
 25. The system of claim24, where the generated code is created for a first version of aparticular device that is different from a second version of the targetdevice, and where, when generating the executable constraints document,the processor is to: generate the executable constraints document basedon information provided regarding the generated code during a creationof the generated code for the first version of the particular device.